1. Field of the Invention
This invention relates to a method of preventing burning resonance noise and a burner plate on which a primary burning is effected with a high heat capacity.
2. Description of Prior Art
In a burner apparatus, a burner plate is provided which has a multitude of fire holes each piercing through its thickness. The burner plate is placed between an upper end of an air-fuel passage in which a burner fan is disposed and a burner chamber in which a primary burning is effected with a high heat capacity. An acoustic system is formed which has a certain volume and configuration determined by the burner chamber, the air-fuel passage and an exhaust passage led from the air-fuel passage. The acoustic system has a characteristic frequency, and an acoustic resonance frequency appears to induce a burning resonance noise when a frequency response of a resonance burning heat frequency in the burner chamber has a certain relationship with the characteristic frequency of the acoustic system. The acoustic resonance frequency is induced when a phase of the frequency response of a resonance burning heat frequency is in a superposing relationship with a phase of the characteristic frequency of the acoustic system.
Therefore, it is one of the objects of the invention to provide a method of preventing burning resonance noise by effectively altering frequency characteristics of burner flame so that the phase of the frequency response of a resonance burning heat frequency is not in a superposing relationship with a phase of the characteristic frequency of the acoustic system.
It is also one of the objects of the invention to provide a burner plate which is capable of preventing the burning resonance noise when a primary burning is effected on the burner plate with a high heat capacity.